1. Technical Field
The present invention relates to a technique for replacing a toner supply container of rotary image forming apparatus having a rotary body with plural developing devices.
2. Related Art
A so-called rotary image forming apparatus that develops an electrostatic latent image formed on a photosensitive drum, using a rotary developing unit having plural developing devices provided at the circumferential surface of a rotary body is known. In such apparatus, developing operations using toner of each color are sequentially performed by, for example, rotation of a rotary developing unit so that one of the plural developing devices faces a photosensitive drum, and causing the developing device to develop an electrostatic latent image formed on the surface of the photosensitive drum with toner of a first color, and subsequently by rotation of the rotary developing unit so that another of the plural developing devices faces the photosensitive drum, and causing the developing device to develop the electrostatic latent image formed on the surface of the photosensitive drum with toner of a second color, and so on. As a result, toner images are layered on the photosensitive drum.
A commonly-used rotary developing unit has a toner supply container which is known as a toner cartridge, and an appropriate amount of toner is supplied from the toner supply container to each developing device.